1. Field of the Invention
The present invention relates generally to wireless telecommunications and more particularly, to a device and method for exchanging frame messages having multiple lengths in a CDMA communication system.
2. Description of the Related Art
At present, mobile communication systems using CDMA (Code Division Multiple Access) technology have become increasingly widespread. Conventional CDMA mobile communication systems based on the TIA/EIA IS-95 CDMA standard transmit control signals for call processing multiplexed with data on a traffic channel carrying voice information. The traffic channel has a fixed frame length of 20 ms. Two techniques have been proposed for transmitting communication signal traffic with control signal traffic: a xe2x80x9cblank-and-burstxe2x80x9d technique and a xe2x80x9cdim-and-burstxe2x80x9d technique. The former transmits the whole frame as a control message and the latter transmits the control signal by sharing the frame with main user traffic.
CDMA communication systems that provide multimedia services including packet data service as well as voice service are coming of age. These new systems may separate channels for the voice and data services to flexibly allocate the channels at the user""s request. To this end, the CDMA mobile communication system includes a voice traffic channel (or fundamental channel) and a packet traffic channel (or supplemental channel).
Conventionally, for the data service through the fundamental channel and the supplemental channel, CDMA mobile communication systems typically maintain use of the fundamental channel to transmit control signals, even in a state where there is no communication between the base station and mobile station. This results in a waste of channel resources, thereby limiting radio capacity. In addition, the conventional CDMA mobile communication system uses the fixed single frame length of 20 ms without regard to the size of a message to be transmitted, which may cause low throughput and traffic delays.
It is, therefore, an object of the present invention to provide a transmission/reception device and method for exchanging frame messages of different lengths in a CDMA communication system.
It is another object of the present invention to provide a transmission device and method for intermixing frame messages of different lengths in a CDMA communication system.
It is still another object of the present invention to provide a reception device and method for receiving intermixed messages of a first length frame message and a second length frame message in a CDMA communication system.
In accordance with an illustrative embodiment of the invention, in a transmission device and method for a CDMA communication system, when a shorter frame message is generated during transmission of a longer frame message, the transmission of the longer frame message is interrupted, whereupon the shorter frame message is immediately transmitted in place of a portion of the longer frame message. In one embodiment, after the longer frame message is interrupted and the shorter frame message is transmitted, the tail portion of the longer frame message is transmitted thereafter. That is, the replaced portion of the longer frame message is not transmitted following the shorter frame message transmission. In an alternative embodiment, following the shorter frame message transmission, the remainder of the longer frame message, from the point of interruption, is transmitted in its entirety. In the latter case, the longer frame message is delayed by the length of the shorter frame message. In another alternative embodiment, following the shorter frame message transmission, the remainder of the longer frame message is discarded.